The present invention is related to a rotary blood pump. More specifically, the present invention is related to an implantable centrifugal blood pump in which the blood flow through the pump can be identified without any invasive sensor.
One concern associated with the implantation of a blood pump is the clotting of blood due to the presence of the pump in the blood circulatory stream. Any edge or crack or protrusion, for instance, that contacts the blood flow could serve as a location where blood could collect and clot, or cause disruption of the blood and result in blood clotting.
To minimize the possibility of a blood clot, it is desirable to minimize edges or protrusions present in the blood flow path. One approach to meeting this constraint is to avoid the use of any sensor that would introduce an edge or protrusion in the blood flow path. However, it is also important to know the flow of blood through the pump. It is thus desirable to be able to identify the flow of blood through an implanted pump without the presence of sensors in the blood flow path.
More problematic, the presence of sensors in an implanted pump will increase the need for separate wires, or connections to the sensors, through the patient along which the signal integrity must be reliably maintained. Because the implanted pump and supporting wiring for current to power the pump are already quite intrusive, it is desired to avoid any additional wires having to be present to connect to the pump through the patient. For this reason, it is desired not to need sensors and thus additional associated wires extending from the sensors through the patient.
The present invention provides for the identification of flow through the implanted pump in the heart without the need for any flow sensors. When a bi-ventricular assist is needed, this invention can be used to regulate the pump flow rate on both sides of the heart to ensure balanced device outputs.
The present invention pertains to an apparatus for moving blood in a patient. The apparatus comprises a blood pump adapted for implantation into a patient. The blood pump has a moving mechanism which contacts blood and imparts energy to the blood to move the blood in the patient at a desired flow rate. The apparatus comprises a mechanism for causing the moving mechanism to move the blood. The causing mechanism is engaged with the moving mechanism. The causing mechanism receives energy to power the causing mechanism. The apparatus comprises a flow indicator connected to the blood pump to identify the flow of blood through the pump based only on an energy balance between the energy imparted to the blood by the moving mechanism and the energy received by the causing mechanism.
The present invention pertains to a method for determining blood flow in a patient. The method comprises the steps of providing energy to a blood pump implanted in a patient to operate the pump. Then there is the step of imparting energy to blood in the patient with the blood pump at a desired flow rate. Next there is the step of identifying the flow rate only by balancing the energy imparted to the blood with energy provided to the pump.